MIDI

Question 1

MIDI

Answer 1

A. A protocol for data communications between devices

B. Way for computers and instruments to talk to each other

Question 2

MIDI cont.

Answer 2

A. Standardization, all equipments from manufacturers can communicate with others

B. Allow more then one sound at the same time

Question 3

MIDI Modes explained

Answer 3

A. Omni on/off

Omni on: device will receive messages on all channels
Omni off: device will receive messages on a specified channel

B. Poly/mono

Poly = instrument can play multiple notes per channel, up to limit
Mono = Instrument can play one note per channel

Question 4

Omni On/Poly

Answer 4

1. Simplest mode. Slave device responds regardless of channel number
2. Will play all notes sent up to the capability of the device

Question 5

Omni On/Mono

Answer 5

1. Rarely used, useless

2. Slave responds to notes on all channels but can only play one note at a time

Question 6

Omni Off/Poly

Answer 6

Slave will respond to polyphonic note data but only if master/slave set to same channel

Question 7

Omni Off/Mono

Answer 7

1. Useful for Multitimbral Synthesizers

2. Different patches can be assigned to different channels, and single synth can sound like several

Question 8

Multi Mode

Answer 8

1. Omni off/mono mode: Can assign polyphony to each voice, like several synthesizers
2. Most useful and popular mode

Question 9

Dynamic Voice Allocation

Answer 9

1. In Modern synths, along with Multimode
2. Do not need to assign number of playable notes to each channel, computer decides how many notes to give to each channel

Played in synthesizer up to the maximum polyphony

Question 10

Serial Binary Data

Answer 10

1. Serial: Messages sent in order one at a time

2. Binary: Cables only send voltages equal to 1 or 0

Question 11

Status bytes

Answer 11

1. Specifies type of message and how many additional data bytes follow to make up complete message
2. Most significant bit is ALWAYS 1

Question 12

Data bytes

Answer 12

1. Gives the values being sent
2. Most significant bit is ALWAYS 0
3. Use of MSB to determine type of value limits data bytes to 128 values (0 to 127)

Question 13

Channel Voice Message: Note On

Answer 13

Includes 3 bytes

• Status byte
• Data byte #1: Remaining 7 bits are MIDI pitch (0-127)
• Data byte #2: Remaining 7 bits are MIDI velocity (0-127)

Question 14

Polyphonic key pressure

Answer 14

1. Senses key pressure for each individual note, “after touch”
2. needs extra byte to indicate pitch
3. could be used to control volume, vibrato, brightness etc. on device

Question 15

Program Change

Answer 15

Only 128 patches specified, no guarantee same sound will be in the same program number

Question 16

Control Change

Answer 16

1. Message sent when controller value changes
2. Continuous (0-127) or on/off (0 or 127)
3. Numbers 32-63 exist to allow 0-31 to have a high resolution
4. 120-127 reserved for channel mode messages

Question 17

Fixed Controller Numbers

Answer 17

1 = Modulation wheel
4 = foot controller (gas pedal)
66 = sustain pedal

Question 18

Pitch bend

Answer 18

1. Special case of control change, with own status byte (1110cccc)
2. Needs better resolution, two data bytes are used to give 14-bits (16,384 values)

Question 19

Bank Select

Answer 19

1. Type of Control Change
2. MIDI allows group programs into up to 16,384 values (14-bit banks)
3. Allows selection of program beyond 127 by assigning it to another bank and selecting that bank

Question 20

Most Significant Byte

Answer 20

One of three bytes: control change, bank select, and Most significant byte of bank number (7 bits only)

Question 21

Least Significant Byte

Answer 21

• One of three bytes, control change, bank select, and Least significant byte of bank number (16,384 values = 14-bit)
• Number farthest to the right

Question 22

System Exclusive Messages

Answer 22

1. Parts unique to manufacturer I.e. exact setup for each patch
2. Can also turn GM on/off

Question 23

Editor/Librarians

Answer 23

System exclusive messages use these programs to edit sysex info

Question 24

MIDI Interface

Answer 24

Keyboard or hardware device used for communication between computers, and send 16 channels of MIDI

Question 25

Multiport Interface

Answer 25

1. Allows computer to send out 16 channels of MIDI out of each 8 MIDI ports 2. Max. 128 different patches to be used 3. Need to specify top to bottom: port, channel, and patch

Question 26

Standard MIDI File

Answer 26

Time work, format expresses tempo as "the amount of time per quarter note"

Question 27

Delta time

Answer 27

1. Difference between the previous event and current one expressed in MIDI clock pulses 2. Delta time of 0 means simultaneous events 3. Speed of clock pulses depends on tempo setting

Question 28

PPQN

Answer 28

Standard for delta time (Pulse per quarter note)

Question 29

Ticks

Answer 29

Specific number of PPQN available in sequencer

Question 30

General MIDI

Answer 30

1. No agreement on what sound would be at what patch, Instrument Patch Map 2. Middle C is MIDI pitch 60, modulation wheel, pitch ben etc. implemented 3. Still some limitations, although has increased popularity of MIDI

Question 31

Instrument Patch Map

Answer 31

1. List of 128 sounds and MIDI numbers 2. Grouped into 16 families each with eight variations 3. Percussion key map

Question 32

Percussion key map

Answer 32

Percussion is always on channel 10, part of instrument patch map